This invention relates to a cassette for accommodating optical waveguides with excess lengths and optical waveguide splices, break-out webs and circular guide elements for the optical waveguides introduced and splice fixing means for the optical waveguide splices being arranged on a cassette base plate.
EP 0 872 750-A2 discloses a cable sleeve with a retaining arrangement for cassettes for storing and splicing optical waveguides. The individual cassettes are arranged for swing action on a cassette carrier, the cassettes being arranged one above the other and being capable of being swung upward into operating positions. Two circular guide elements with break-out webs are located on the cassette base plate, with the result that it is ensured that optical waveguides introduced cannot spring out of position.
DE 44 38 668-A1 discloses a cassette which is intended for storing optical-waveguide excess lengths and optical waveguide splices and comprises one or more basic modules. These basic modules are each of the same basic construction and may be assembled, depending on requirements, with the aid of connecting elements. Here too, circular guide elements are provided for the optical waveguides.
WO 95/07482, furthermore, discloses a cassette for accommodating optical waveguides with excess lengths, the optical waveguides being introduced and/or led out at groove-like inlets. The excess lengths here may be positioned around approximately circular guide elements. Here too, break-out webs prevent the optical waveguides introduced from springing out.
An object of the invention, then, is to provide a cassette for accommodating optical waveguides with excess lengths that can be used, and is optimized, as universally as possible for a wide range of different use purposes in respect to the arrangement itself, in respect to the variety of inlet ports for the wide range of different types of optical waveguide and in respect to the accessibility.
One object set is achieved according to the invention by a cassette of the type mentioned in that there are provided two circular guide elements and a cross-form guide element, located between the two circular guide elements, for the optical-waveguide excess lengths, in that differently shaped splice-protection holders are provided for accommodating different embodiments of splice-protection elements, in that pivoting elements are provided both for vertical and for horizontal pivoting of the cassette, in that the introduction regions are equipped for the introduction of optical waveguides and/or optical waveguide strips and/or optical waveguide connectors, and in that additional elements and/or accessories are arranged on the cassette base plate for adaptation to the respective use purpose.
One advantage of the cassette construction according to the invention over the prior art is that this cassette can be used for accommodating a wide range of different configurations of optical waveguides, such as individual fibers, strips or bundle tubes or optical waveguide terminations, such as optical waveguide connectors, in particular so-called pigtails, which are optical waveguide ends with connectors fixed thereon. A further advantage is that satisfactory guidance of the optical waveguides introduced is ensured by two circular guide elements, which maintain in each case the permissible minimum radii of the optical waveguides, and by a cross-form guide element located therebetween, the possibility of guidance in a FIG. 8 making it possible to reach every outlet and inlet point of the cassette. In the case of the introduction of optical waveguides with connector termination (pigtail), an accommodating adapter may be inserted in front of the inlet ports of the cassette base plate, arrangements for accommodating the connectors being located on said adapter. Likewise on this inlet side, a vertical pivoting element may be attached there, which makes it possible for the cassette base plate to be swung down laterally from a vertical position. A corresponding step-design holder for vertical pivoting makes it possible to achieve the situation where, by virtue of cassette base plates that are arranged one beside the other being pivoted down laterally, access can be gained to said base plates without them having to be removed from the cassette assembly.
A further advantage is that corresponding arrangements and installations in the form of splice holders make it possible for all possible types of optical waveguide splice protectors to be fixed on the cassette base plate. Moreover, additional elements or accessories are latched, or fixed by break-out webs, in the interiors of the circular guide elements, it being possible for these, depending on the use purpose and requirements, to be removed or broken off. With the aid of these additional elements or accessories, it is possible to assemble, for example, cassette base plates to form stacks, the access to each individual cassette base plate being maintained. For this purpose, for example, hinge parts and closure clips are required. Moreover, mounts for optical waveguide strips or individual optical fibers are fixed in the same way in the interiors of the guide elements or accessories, it being possible for these, following removal, to be inserted into the respective regions of the inlet ports on the cassette base plate. Finally, in this exemplary embodiment, special fastening elements are also provided as additional elements or accessories, it being possible for the cassette base plate to have these fitted on the outside, either on the narrow side or on the rear plate side. With the aid of these fastening elements, it is then also possible for said cassette base plate to be fitted, and fastened, on corresponding mating elements on the framework or the like.
Furthermore, a cassette transition is provided in the central region of the cassette base plate, on the longitudinal pivoting side, it being possible for optical waveguides to be passed on from one cassette to a parallel cassette by way of said transition.